Abstract In Democracy in America, de Tocqueville makes two claims about scientific inquiry in democracies: first, that in the abstract there is nothing essential about democracies that prevents them from achieving in science; and second, that in practice democracies will bend science toward practical applications. This paper will examine the nature of the compatibility of science with democracy within a literature roughly called ?liberal social thought?, using de Tocqueville's claims as an organizing principle. In assessing the first claim, the paper identifies three tensions between science and democracy?the populist, the plutocratic, and the exclusionary?the last of which is an essential tension, as it is grounded in the exclusionary nature of the rationality common to both science and liberal democracy. If one rejects the rationality of scientific inquiry, one risks being excluded from political inquiry and political rights. In assessing the second claim, the paper views the professionalization of science and the idea of a ?republic of science? as embodying the exclusionary tension and thus as being undemocratic. The exclusionary tension underlies many current conflicts in science and democratic governance